The Dar es Salaam Marine Reserves are unique due to their proximity to the city, potential biodiversity and richness, good scenic diving and snorkelling sites, marine birds and dolphin viewing. Occasionally hunchback whales are spotted in the deep waters around the reserves from May to August. The islands are open to visitors during the day and have bandas (shades), information boards and nature trails. Drinks and freshly cooked fish can be purchased from local community members, who also serve as tour guides and rangers.

Mafia Island, located 120 km south of Dar es Salaam, is surrounded by some of the richest reefs in the world, with over 50 types of corals and 400 species of fish identified so far. Mafia’s best diving is at depths less than 30 m where you can see most kinds of tropical marine habitats, including exposed fringing reefs, rock walls, soft coral and algae dominated reefs. Large predatory fish and turtles are common and mostly unaffected by approaching divers. Chole Bay, Mafia's protected deep-water anchorage, is part of the protected marine park. The diving here is amongst the most spectacular in the world and includes colourful coral gardens, walls at various levels and many shelves and coral heads.

Maziwe Island Marine Reserve, situated 15 nautical miles east of Pangani, has over 350 fish species, 35 genera of coral and an abundance of shoreline birds. Maziwe Island was designated a reserve in the 1970s as a way to lessen the erosion caused from the cutting of trees for firewood. The island now only emerges from the sea at low tide and is an ideal place for swimming, snorkelling, diving and sunbathing.

The Mnazi Bay – Ruvuma Estuary Marine Park, located in southern Tanzania, on the Mozambique border, is home to important populations of whales, dolphins, four species of turtle and numerous birds. The area is recognised as being internationally important for its biodiversity, with mangroves, sea grass beds and coral reefs. There are 12 villages in the area and it is hoped that visitors to the marine park will help the local economy of this area, one of the poorest and least developed in Tanzania.

Chumbe offers some of the most pristine and colourful coral reefs to be found with over 200 species of coral providing a sanctuary for more than 400 species of colourful fish. To protect these coral reefs, diving is not permitted in the marine park. The reef is shallow enough to see everything very clearly with a mask, snorkel and fins. There is also a coral-rag forest which is home to the endangered Ader's duiker, giant coconut crabs, hermit crabs and a variety of bird species. Knowledgeable guides take guests on daily snorkelling and forest tours. Chumbe can be visited for day trips or longer, staying in ‘eco-bungalows’ overlooking the Indian Ocean. Chumbe Island contains a lighthouse, built by the British in 1904 and still operational, a ruined mosque and the lighthouse keeper's house, now converted into a spectacular education centre and restaurant. All profits from tourism on Chumbe Island are reinvested into the conservation and education programs operating in the Park, and the island is staffed and managed by local Zanzibaris from the fishing community, with voluntary support from overseas experts.

In the southwest of Zanzibar Island, near Fumba to the west and Unguja Ukuu to the east, Menai Bay is a sea-turtle breeding area and also encompasses several coral reefs, an abundance of marine life and dense mangrove forests. It is also famous for its humpback and bottlenose dolphins. It extends from the south west corner of Zanzibar Island encompassing several small islands and sand banks each with its own spectacular coral reef. Traditional boats make regular trips for snorkelling on the reefs, picnics on the islands and the star attraction of swimming with dolphins and whales.

Misali Island, located just west of Pemba, has some of the highest recorded coral cover, and high species diversity with 40 genera of coral and 350 fish species. The one sq km of terrestrial area supports endangered nesting turtles, and the dense coastal thickets harbour populations of green monkeys, the endangered and endemic Pemba Flying Fox, globally endangered coconut crabs and various species of birds. Economically fishing at Misali provides direct livelihood support to 11,400 people. There is a non-extraction zone that covers part of the total conservation area. Recreational activities such as diving and snorkelling, passage and scientific research are permitted within the non-extraction zone, but any type of activity that depletes the area’s natural resources is not allowed (such as fishing or shell and coral collecting).

Mnemba Island is located about 4.5 km off the north-eastern tip of Zanzibar Island. The island is 1.5 km in circumference and is surrounded by spectacular coral reefs. Turtles lay and hatch their eggs all year round and there is excellent diving and snorkelling. The only human inhabitants of the island are the staff and guests staying at the exclusive, luxury lodge.